Safety control for water-cooled refrigerative systems



Sept. 14, 1954 D S 2,688,849

SAFETY CONTROL FOR WATERCOOLED REFRIGERATIVE SYSTEMS Filed Sept. 13, 1951 EVAPOKATOR.

THERMAL 5 VALVE. #9 RELIEF VALVE. 4 I

COMPRESSOPL CONDENSER.

Z & 13

i 13 WATER. REGNALVE.

INVENTOR. John M.Andrews BY Q L Ai'l'orneys .liquid -sup y- Patented Sept. 14, 1954 S'AFETY"GO"NTROL FOR WATER-COOLED REFRIGERATIVE SYSTEMS ware *i lpplication 'september 13, 1951, Serial No. 246,'3-81 .4-Claims. .1

Thiszinvent-ion relates to refrigeration systems .using a. liquid cooled condenser, :and;provides a simple and-satisfactorily sensitive means for controlling the rate OfCOOllIlg \liquidisuppl'ygand .forshutting- 'dowmthe:system upon failure of In the "ensuing w discussion '1 the cooling liquid will be "assumedato the waterpasis the usual practice.

.aAccording to the invention, ihot gas entering the condenser from =the compressor is directed against-a water tube through which 'coolingrwater leaves the icondenser. :The 1 thermal -bulb 'which regulates the rate of cooling-water'flow-lis subject to the temperature of water so heated and preferably is locatedirr theitube.

The supply of motive-energy to the-compressor is subject on an on-and-off .basis to thecombined'efiect of the temperature of the water and the temperature "of hot gas "entering .the icondenser.

In this' way "sufficiently rapid response is assured using "a" mechanism "which: is simpler. and lessexpensive than *those heretofore considered necessary.

A typical "embodiment'of the invention .willbe described by reference "to the iacconipanying drawing in" whichthe "singlefi'gure is a i'diagrammat-ic="elevation'(with'parts"broken away) of a refrigerative circuit embodying the invention.

In the drawing the numeral l indicates the shell of a Water cooled condenser which is cooled by internal water coils to be described. Refrigerant condensed in shell I passes by liquid line 2 to a controlling device 3, which may be an expansion valve or the equivalent. This delivers liquid refrigerant at appropriate rates to the evaporator 4 of any suitable type.

The suction line 5 leads from the evaporator 4 to motor driven compressor 6 which compresses refrigerant evaporated in evaporator 4 and delivers it through the hot gas line 1 to the condenser shell I. The device 8 is a relief valve which in response to excessive pressure vents line 1 to line 5. This is commonly required by the underwriters in water cooled systems.

The circuit above described is simply a typical compressor-condenser-evaporator unit which may conform to any accepted practice, and for which no novelty is here claimed. It is typical of the environment in which the invention offers its characteristic advantages.

Outside shell I are two water manifolds, a supply manifold 9 and a discharge manifold I l connected by a plurality of water tubes l2 which extend in parallel through the shell Water is supplied from ::city :mains rthrough 'pipe [i3 and water :regulator valve 1 .2 B rto :tsupply :mamfold Thence .iit passes :through ztube's [2 :to :manifold M, sand exchanges :heat with Fthe :compresse'd refrigerant 'svapor ineshell l. lManifold .H Edischarges rto any point of use'of warm water or to waste as*circumstances'dictate.

According to -theinvention,-'hot gas line 'l discharges into -shell through --a tube 14 -wh-ich 'has'nozzle'ports 1 5 directed .tow-ardone of the tubes i F2 nearthe water exit end thereof. "Thus sets of "hot gas impinge .directly -'on this tube which is the uppermost tube in --the -'drawing. Thus'the hcttest'-vapor exchanges heat with the warmestwatenwith the result that any water failure 1 results 1 in #aesharp temperature rise.

In the 'prior art it has 3 been "proposed to =-subject a thermostatic bulb containing -'a -Volatile liquid to the condenser poolin water, and *use the resulting vapor'pressure to open a water regulating Waive more and i more i in response -to rising temperaiarre. v alve 2-8 is biased to closegbut is urged in its openin' direetion by*pressure in tube H 6 -wl'iich leads from thermostatic bulb 1 I I. valve-12c -is orien -whenever thecompressor is -op 'erating but may close if the-compressor remains id lei'for -extended periods. Thus' 2!."S3Vi1lg in 'the amount of water used is effected. According to the invention, bulb 'l'! is located within a tube l2 adjacent the area of hot gas impingement. The thermostatic water valve is known. The novel feature is the location of bulb H.

A thermostatic switch [8 is mounted on a copper plate [9 brazed to tube l4 (but outside shell I) and also to that tube I2 in which bulb I1 is located. Switch l8 controls the motor of motor-driven compressor 6 either directly or through any suitable relay switches (not shown). Switch I8 is conventional, but is preferably of the type which will. open to stop the compressor when a predetermined maximum temperature is attained and will start the compressor when the apparatus has cooled to a somewhat lower temperature. The difference between these control temperatures is such that short cycling of the unit is prevented.

As a consequence the thermostat of switch I8 is affected by the hottest vapor and the warmest water cumulatively so that overloads and Water failures each become effective to stop the motor. Any good heat conductor could be used for plate [9, copper being probably the best 10W cost material available.

The construction is simple and independent of condenser pressure as such. Hence leakage from the refrigerative circuit is not a problem. The switch 18 or equivalent device is external to the refrigerative circuit and always accessible. Response is much more rapid than can be had with prior art locations of the thermostatic devices. Finally, the scheme meets the underwriters specifications without involving undue complication and expense.

The illustrated embodiment is, of course, exemplary and subject to modification within the scope of the claims.

What is claimed is:

1. In a refrigerative circuit of the compressorcondenser-evaporator circuit type having a water-cooled surface condenser, and a thermostatically controlled regulating valve for varying the flow of cooling Water through said condenser, the improvement which comprises means for directing at least a major portion of the hot gas entering the condenser against a minor portion of the water-cooled heat exchange surface of the condenser close to the point of cooling water exit whereby a portion of the cooling water is intensively heated, the thermostatic element of said valve being located in the cooling water near said minor portion of the heat exchange surface whereby it is subject principally to heat exchange with the water so heated intensively.

2. A refrigerative circuit comprising a motordriven compressor; a water-cooled surface condenser; an evaporator; water connections through which cooling water passes to and from said condenser; refrigerant connection completing the circuit and including a hot gas line which leads from the compressor to the interior of the condenser and there discharges against a minor portion of the water-cooled surface close to an exit connection for cooling water to afford localized intense heating of a portion of the exit water; and a thermostatic controller for the motor which drives the compressor, said controller being subject at least in part to the temperature of water so heated intensively.

3. A refrigerative circuit comprising a motordriven compressor; a water-cooled surface condenser; an evaporator; water connections through which cooling water passes to and from said condenser; refrigerant connections completing the circuit and including a hot gas line which leads from the compressor to the interior of the condenser and there discharges against a minor portion of the water-cooled surface close to an exit connection for cooling water to afford localized intense heating of a portion of the exit water; and a thermostatic controller for the motor which drives the compressor, said controller being subject to the combined effect of the temperature of the hot gas entering the condenser and the temperature of the water so heated intensively.

4. A refrigerative circuit comprising a motordriven compressor; a Water-cooled surface condenser; an evaporator; Water connections through which cooling water passes to and from said condenser; refrigerant connections completing the circuit and including a hot gas line which leads from the compressor to the interior of the condenser and there discharges against a minor portion of the water-cooled surface close to an exit connection for cooling water to afford localized intense heating of a portion of the exit water; a thermostatic controller for the motor which drives the compressor, said controller being subject to the combined effect of the temperature of the hot gas entering the condenser and the temperature of the water so intensely heated; and a thermostatically controlled regulatory valve interposed in said water connections to vary the flow of cooling water and subject to the temperature of exit water substantially at the point of said intense heating.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,362,757 Stokes Dec. 21, 1920 1,402,418 Hansen Jan. 3, 1922 1,701,753 Goosmann Feb. 12, 1929 1,854,402 Goosmann Apr. 19, 1932 1,907,603 Steenstrup May. 4, 1933 2,057,101 Kagi Oct, 13, 1936 2,188,350 Holmes Jan. 30, 1940 2,318,891 Sidell May 11, 1943 2,356,261 McGrath Oct. 22, 1944 ,572,582 Andrews Oct. 23, 1951 

